A method to remove heavy metals from wastewater by modifying the surface of a PVDF membrane using chitosan and PANi and assessing it using the Hermia model

Despite the commercialization of several promising technologies for removing organic contaminants from wastewater, industries still face challenges in removing both the organic and heavy metals. In this research, PVDF is combined with biopolymer chitosan (CS) and polyaniline (PANi), a conducting polymer known for its nitrogen-containing functional groups, which bind to heavy metal ions. It was observed that the addition of CS and PANi has altered the roughness of PVDF due to hydrophilic nature of CS and PANi allowing the membrane to trap more water, thereby aiding it in the removal of heavy metals. The permeate flux and sulfamethazine removal showed that the membrane modified with CS & PANi showed a better removal, exhibiting a lesser fouling characteristic when compared with the pure PVDF membrane. Moreover, from Hermia's model, we were able to evaluate membrane effectiveness, and it was observed that the complete pore-blocking model aligns more closely with the experimental data compared to the other models examined. The heavy metal removal studies proved that almost 95 % of heavy metals (lead and cadmium) were removed from the bulk solution in the CS, PANi modified PVDF membrane with higher PANi concentration, whereas for pure PVDF membrane, less than 15 % has been achieved. This research aims to offer a more effective solution for wastewater treatment by targeting heavy metal contamination, contributing to cleaner water and environmental sustainability.